Liquid fuel burner



June 7, 1938.

R. M. SHERMAN LIQUID FUEL BURNER 2 sheets-sheet 1 Filed Jan.. 25, 1936Iawenior:

June 7, 1938.

' R. M. SHERMAN LIQUID FUEL BURNER Filed Jan. 25, 1956 2 Sheets-Sheet Ihm w. I

l atented June 7, 1938 v A I 4 v UN E S-PATENT OFFICE LIQUID FUEL BURNERRallston M. Sherman, Glastonbury, Conn, as-

- signer to The Silent Glow Oil Burner Corporation; Hartford, Conn.,a-corporation of Connecticut Application January 25, 1936, Serial No.60,832 3 Claims. (c1. 158-76) This invention relates to apparatus forburning and discharged forwardly through a prolonged liquid fuel (hereinreferred to for descriptive purstraight tubular air conduit 21 intowhich the poses as oil), and deals more particularly with impellerhousing merges. burners of the so-called gun type. Positioned axiallywithin the conduit is the oil The invention has among other objects thedelivery pipe 29 terminating just short of the 5 conservation of heatimparted to the combusconduit mouth in a nozzle 3|, the pipe 29 havingtion chamber of such a burner, the providing of connection at its rearend to the oil supply pipe ,simple and effective means for adjusting theair 33 entering the conduit laterally. Oil is supplied supply to theburner, and means for effectively under pressure to the pipe 33 from theoil pump, directing the air from the air impeller to the the latterbeing fed from a main storage tank, 10 burner. not shown. The pressuremaintained and the These and other objects of the invention will form ofnozzle provided are such as to cause the be best understood from thefollowing descripdischarge of oil from the nozzle, without'pretion whentaken in connection with the accommixture of air, in the form of acone-shaped spray l5 panyihg illustration of one specific embodiment ofmechanically atomized oil.

thereof, while its scope will be more particularly To ignite thecommingled oil and air the usual pointed out in the appended claims.sparking electrodes 35 are employed, positioned In the drawings: v inadvance of the nozzle and connected each to Fig. 1 is a plan view,partly in section, showing a conductor 31, the latter being mounted inrigid, the principal working parts of a burner emb'odynon-conductingsleeves 39 of porcelain or other 20 ing one form of the invention. likeinsulating material, the conductors entering Fig. 2 is an elevationshowing the 'air control the conduit through the bottom thereof, 'asindevice in closed position and looking from the dicated in Fig. 3.front or nozzle end of the burner; On the installation of the burner,the forward Fig. 3 is a. central, vertical section of the rear end ofthe conduit is entered into and sealed with- 5 part of the burner shownin Fig. 1 but on an en in the wall 4| of the furnace (Fig; 1), the openlarged scale; and mouth terminating preferably substantially flush Fig.4 is a section on the line 4-4 of Fig. 3 with the inside of the wall ofthe combustion looking at the air control device from the imchamber andthe combustion chamber being prefpeller end of the burner. erably sealedagainst any substantial admission of 30 Referring to the embodiment ofthe invention air other than that-entering through the conduit. heresubmitted for illustrative purposes, the burn- In the operation of aburner of this type, when er is equipped (Figs. 1 and 3) with a rotaryair the burner is stopped, as by the actuation of a impeller ll-of theso-called Slrroco type having a room thermostat with the resultantstoppage of central air intake l3. The impeller is mounted on the, motor2| and impeller oil delivery ceases 35 a driving shaft l5 and comprisesa disc I I and an and the forced draft created by the impeller stops.opposed spaced annular plate IS with interposed But, unless preventativemeans are provided, the connecting multiple vanes or blades.- On onecombustion chamber remains open to the conside of the impeller andconnectedto the driving tinuous passage of a current of cold air throughI 4 shaft I5 is mounted an electric driving motor 2| fthe air conduitwhich, on the stoppage of the on the pp s Side the Shaft m y be burner,i's-accelerated or intensified by the draft connected to the usua o l pp (not herein through the heated chimney. This tends quickly shown) tochill the walls of the combustion chamber and e impeller is l r ihousing the the heat transfer wallsof the furnace, depriving .45 upperpart of which is of generally cylindrical form, having its end wallfacing the motor closed resumn g 1n a large and unnecessar heat wastage.fi gg g g g gg through 33 fi For the effective conservation ofsuchprevious-' sa exens,an eoppose eoren wa v preferably with an airadmission opening 25 1y imparted heat and ,a more efficient operationaligned with the opening in the annular plate l9 oi the fuel burningapparatus as a whole there is 5 ofthe impeller, herein provided meansfor s ubstantially cutting The mp 1 u t d i eccentric relation offfurther delivery of air from the air conduit as r to the peripheral wallf the housing d soon as the burner ceases to function and the air tatesin the'direction of the arrow shown in Fig. impeller comes to s t y p tn the I u 3, the air being drawn into the central air intake walls ofthe combustion chamber and the furnace 5 them of the heat previouslyimparted thereto and finger 51 of each blade, as indicated by dotted Ifrom the chilling effect of the otherwise cold en-. tering air.

In the illustrated embodiment of the invention, such means is in theform of an automatically acting-air valve or shutter device (indicatedin Figs. 1 and 3 generally by the numeral 43) located in the air conduititself and preferably closely ad- Jacent the air receiving end thereofbetween the nozzle and the impeller, such device being adapted to openautomatically for the free passage of air when the impeller is operatedbut to .close auto matically when the impeller is stopped.

With such device means are also provided whereby the amount of airdelivered by the air conduit when the burner is in operation may bepredeterminately adjusted, the usual air valveor shutter at the airsuction end of the impeller being unnecessary. Such device is alsopreferably so arranged'as to beneficially control the path of the airthrough the conduit.

This device (as best shown in Figs. 2, 3 and 4) comprises a series ofmetallic blades 45 (herein six in number) approximately flat, each bladebeing of generally triangular shape with an outer arcshaped edge. Eachblade at the inner and outer ends of one-edge has a small corner flange41 bent at right angles, by means of which flanges the blade ispivotally mounted on a pin or small rod 49 and on which it is held bythe small ,discshaped cap piece 5| fixedly secured on the end of thepin. Each rod is fixedly secured to the sleeve 53, and projects radiallytherefrom, the pins being equally spaced around the periphery of thesleeve.

The sleeve 53 is fixedly secured to the rear end of the oildelivery'pipe 29.

A torsion spring 55 encircles each pin, having one end fixed to thepinand the other extending over and lying against the face of the bladepiv-'- oted on such pin so that normally the blades are urged by thelight pressure of the spring in'a direction causing them to assume aclosed position. or that shown in Figs. 2 and 4 and in full lines inFig. 3. They are held in this closed posi- .tion by the small stopfinger 51 (Fig. 2) projecting from the lower end of the free edge of theblade which encounters and is stopped by-the pivoting pin 49 of'the nextadjacent blade.

The pivoted edge of each blade extends somewhat beyond the pivoting rod49, and 'when the blades are in closed position this extension is thereoverlapped by the free edge of the next adjoining blade. When in closedposition the blades together provide a substantially disc-like closure,substantially fitting the inner cylindrical walls of the air conduit, asshown in Fig. 4, with a minimum of clearance left sufficient onlytoallow the subsequent opening movement of the blades. In such closedposition further passage of air through the conduit is substantially cuton. Y

When the impeller is started into operation, the blades underthepressure of the air delivered by the impeller automatically swing abouttheir pivot points and open into some such position as isindicated bythe dotted lines in Fig. 3, allowing. the free passage through theconduit of air delivered by the impeller. The amount of air sodelivered, however, and the resulting capacity of the air control deviceare dependent upon the extent of the blade opening movement. Thismay bepredetermined and the air supply for the burner definitely fixed by thesimple-use of an adjustable blade stop. Herein this is provided by meansof the collar 59 which is adjustably threaded on the outside of thesleeve 53 in front of the air control device and has its rear edgepresented to the stop lines in Fig. 3, which finger moves forwardly awayfrom the pivot pin 49 when the blade undergoes its opening movement. Thestop collar 59 may be adjusted to any desired position lengthwise of thethreaded portion of the sleeve 53 and there held fixed by a set screworother means. This provides adjustable means whereby the opening of theblades resulting from its adjustment may be limited to any point betweenzero opening and maximum, so that the air supply for the burner may bepreadjusted by varying the extent of blade opening. a r

The adjustable blade stop may be made accessible for ready adjustmenteither by providing a removable section 6| for the top of the airconduit or by splitting the entire casing of the air impeller casing sothat the upper part is removable, as

described in my previously filed application, Serialregularities in thedensity of the air' at different pointsaround the periphery of the airconduit.

It will be observed that when the airis being delivered by the impeller,the blades in openingassume a forwardly pitched relation which tends toconvert the otherwise straight-way progressive movement of the airthrough the conduit into a movement characterized by rotation as well asby 'progressiom'so that the rotative movement of the air thus producedbecomes a true rotative movement of uniform characteristics throughoutthe conduit.

I While I have herein shown and described for the purposes ofillustration .one specific .form' of the invention, it is to beunderstood that extensive deviations may be made in the form, con-'struction and relative arrangement of' parts, all without departingfrom the spirit of the invention.

I,claim: 1. A liquid fuel burning apparatus having a nozzle, for thedelivery of liquid fuel to a combustio'n chamber, an, air deliveryconduit surrounding said nozzle for delivering air 'to said combustionchamber to be commingled with said fuel, an air impeller for forcing airthrough said conduit, means between said impeller and the 'mouth of saidconduit. forautomatically shutting off further substantial passage ofair to the combustion chamber on. the stoppage of the air impeller, thesaid means comprising a series of pivotally mounted blades and aplurality of 'axes extending outwardly from and arranged symmetricallyabout the axis of the conduit on which axes the blades are mounted, saidblades normally forming a substantial closure for the conduit, and meansfor holding said blades closed but yieldable under. the pressure of theair discharged by the impeller to permit them to swingto an openposition to permit the passage of air through the conduit.

2. A liquid fuel burning apparatushav ing' a nozzle for/the delivery ofliquid fuel to a combustion chamber, an air delivery conduit surroundingsaid nozzle for delivering air to said combustion chamber to becommingled with said fuel, an air impeller for forcing air through theconduit, means between said impeller and the having'a central airintake. and means in said 7 conduit near the air-receiving end thereoffor mouth of the conduit for imparting a rotative movement to the airpassing through the conduit and for automatically shutting of! furthersubstantial passage of air to the combustion "5 chamber on the stoppageof the air impeller, the

said means comprising aseries of pivotally mounted blades arrangedaround the axis of the conduit and overlapping to form normally asubstantially disc-like closure for the latter, and

10' means normally moving said blades to a conduit closing position butyieldable when said blades receive the pressure of the air delivered bythe impeller to permit said blades to swing to an open position in whichthey impart rotation to 15' air passing through the conduit.

3. A liquid fuel burning apparatus having a v nozzle for the delivery ofliquid fuel to a combustion chamber, a cylindrical air delivery. conduitsurrounding said nozzle for delivering air 20-t0 said combustion chamberto be commingled with said fuel, a rotary vaned ,air'impeller forforcing air through said conduit, said impeller automaticallyshutting/oil further substantial passage of air to thecombustion chamberthrough said conduit on the stoppage oi the air impeller, the saidmeans, comprising a series-of overlapping, segmental blades and -aplurality of equally spaced, radial axes on which the blades arepivoted, ,said axes extending outwardly-from the axis of the conduit,said blades forming a means for limiting the opening-movement of theblades to predetermine'the'supply'of air deliveredby said air impellerthrough said conduit. v RALLSTON M. SHERMAN.

